Just bought a 67 gto, to redo I checked the vin it was a 242 with the rosseta rivits I think but was so excited I did not check the data plate, but it is a 242 but the numbers does not match, then I found a 67 plate with the original book it says 237. So I dont know what to do, Is the vin tag the one to go? Is it legal, I mean I am sick. Thanks Jim

Man Jim that sounds like a bad situation. What book and plate are you reading the 237 code from? Body code 2337 would be for a Firebird in 1967.
When you say the numbers do not match are you saying that the body plate is properly coded with the number 42 but the 6 digit VIN on it does not match the VIN plate on the car.

both numbers on the vin and data plate are 24207 but the sequence numbers on the data are 202858 and vin100758 should these be the same? then in the glove box I found in the book, these numbers on a metal plate 237177g113427, it was in bad shape but i got the numbers off of it ,I have sent to pontiac for the numbers on the vin. now I just have a bad feeling.

When you say data plate are you talking about the body tag mounted on the left side of the firewall. I just want to be 100% sure that is the tag you are refering to because if it is then yes you might have a problem if the last six on the VIN tag do not match the six digit series of numbers on the top right hand upper corner of that plate. Those numbers should be identical.

Another place to look. This one is very hard to see and harder to change. If you're lucky with a mirror and something like a toothbrush, you might be able to read it. It's on top of the frame rail, drivers side, usually somewhere between the wheel and the bumper. There's also a vin stamped there. If you can find that one, and if it matches one of the other 3 you've found, then that's probably the correct number.

Man Jim I hope it works out ok for you. There are some honest reasons why the body tag and VIN do not match in some cases. People have been known to take two damaged cars and build one good one out of the two of them thats for sure. Then as you fear there are other reasons too. Let us know how you make out and I'll keep my fingers crossed for you.
Bear 's suggestion is a very good idea to see if you can eyeball that other VIN. It would go a long way as to giving you a better idea if the car is just a collection of parts from two cars or if some funny buisness happened at one time.